Steam-boiler



(No'llodeL) J. F. MQENTEE.

.Steam Boiler.

No. 243,386. Patented June 28,1881.

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UNITED STATES PATENT OFFICE.

JOHN F. MCENTEE, OF SAN FRANGISCO,'OALIFORNIA.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 243,386, dated June 28, 1881. Application filed August 23, 1880. (No model.)

To all whom it may concern Be it known that I, JOHN FRANCIS McEN- TEE, of San Francisco, California, have -invented a new and useful Improvcmentin LocomotiveShaped Steam-Boilers, of which the following is a specification.

My invention'relates to the novel manner of attaching a hollow deflecting-plate or waterback within the furnace of a locomotive-shaped [O boiler, so that there may be a perfect circulation of water within said water-back, and that its application within the furnace may be made more conveniently and with less expense than heretofore.

In the accompanying drawings, Figure 1 is a longitudinal sectional elevation of a boiler having my improvements attached. Fig. 2 is a longitudinal sectional plan through line a b, Fig. 1. Fig. 3 is an enlarged longitudinal sectional view through the thimble connecting the water-back t0 the sides of the furnace. Fig. 4 is a plan of the grates.

Referring to the drawings, in which in all the figures like letters of reference refer to like 2-5 parts, A is the shell of the boiler. B are the tubes. 0 is the smoke-box. D is the fire-box or furnace. E is the fuel-door. F is my improved water-back, and G are the connecting pipes or thimbles which attach it to the sides.

0 of the furnace and lead the water from the water-space in the sides of the furnace into the water-back. The thimbles are pieces of pipe with a thread cut on the outside. They are as long as is necessary to screw them from the 3 5 outside of the fire-box through the water-space into the water-back, leaving enough projecting outside the fire-box to admit of a plug or a cap, H, being screwed on to close their ends. (See Figs. 3 and 4.) There are a number of 4.0 holes, I, in each thimble at that portion of their length which will come between the inside and outside plate of the waterspace of fire-box, so that the water may circulate very freely between the water-space and water-back.

It is proper that the upper thimbles be set as near the top of the water-back as possible, so that little or no steam-space may occur in the water-back above them; and, if found desirable, apipe, J, may connect the top of the water-back with the crown-sheet of the furnace, so as to lead off any steam which may accumulate above the upper thimbles; otherwise the top of the water-back might soon burn out from lack of water at that point.

The water-back should be set in front of the tubes, at an angle of about forty-five degrees, according to the size and shape of the furnace. Generally, however, I propose to leave a space of two inches at at, between the lower edge of water-back and tube-sheet, and from six to eight inches at 4 between upper edge of water-back and crown-sheet of furnace.

The water-back may be of cast or plate iron, as preferred, and should have about two and a half inches thickness of Waterspace. It should reach entirely across the furnace, being only enough less in width than the width of the furnace as may be necessary to avoid rivetheads, &c. This water-back deflects the flame arising from the fuel from passing directly through the tubes. Its being set a little distance out from the tube-sheet allows of two aircurrents, one passing up from the grates behind the water-back, and the other over the top edge, both intermingling behind in a sort of combustion-cham her. This action serves, in a measure, to arrest the gases as they are evolved from the burning fuel, andinsures their thorough ignition prior to their entering the tubes, the result being a considerable economy of fuel. The water-back itself givesadditional heatingsurface, thereby increasing the steam-producing power of the boiler.

My next improvement is in the manner of setting the pipes K, which form the fire-grates, th rough which water freely circulates from the boiler. Fig. 4 clearly illustrates this improvement without added description. I will state,- however, that K are the pipes, in two pieces, forming the grates, coupled with sleeve-couplings L, to allowvof the whole being put together.

M are ordinary Ts. N are common gaspipe nipples or short lengths of pipe. 0 are reducers with hexagon flanges, upon which a wrench may be applied. These pipes and fittings are put together, and holes are tapped in the inside of the furnace in such a position as to give the grates a slight slant, that a proper circulation of water within them may be maintained. The grates are then introduced within the furnace and the reducers O screwed out, so as to enter the holes in the furnace made to receive them.

If it is preferred, in some cases the back end of short pipes screwed from the outside through of the grates may be inserted in .the lower end both sheets, forming the water-legs of furnace, of my water-back, as I show in Fig. 1 by dotted said pipes having holes perforated in them belines, thus saving labor and expense in fitting; tween the two sheets, and a screw-cap on outer 15 5 but in such cases the water-back will have to end, substantially as and for the purpose herebe made a few inches deeper. in described.

What I claim as my invention and desire to secure by Letters Patent, is as follows: JOHN FRANCIS MOENTEE' In a boiler-furnace of the locomotive type, Witnesses: 10 the water-back F, when attached to the sides GEORGE PARDY, of the furnace by the thimbles G, consisting MATT. OLARKEN. 

